PROJECT SUMMARY Ischemic cardiomyopathies (ICM) continue to be among the leading causes of death in Western countries. Currently, 5.7 million Americans are living with heart failure, and about 10% have advanced heart failure. Although, many important advances in the treatment of heart failure have evolved during the last decade, most focus only on relieving symptoms and preventing disease progression. Thus, an improved treatment or curative regimen is desperately needed. Our long-term goal is to develop an effective therapeutic intervention for ICM that will improve and prolong the lives of millions of people, and potentially eliminate their disease. Cardiac repair with stem cell therapy has emerged as a promising treatment alternative for the ischemic patient population. Successful generation of induced pluripotent stem cells (iPSCs) and their differentiation into induced- cardiomyocytes (iCMCs) have created exciting possibilities, wherein iCMCs may offer a renewable cell source for therapy, disease modeling and drug discovery. We have generated a safe combinatorial approach using DNA and mRNA of pluripotent factors to reprogram normal urinary epithelial (UE) cells into iPSCs, with subsequent differentiation into functional iCMCs as described by us earlier. Recently, our RNA sequencing analysis of iCMC indicated that small cajal body associated RNA20 (scaRNA20) plays an important?and so far, understudied- role in CMC differentiation. We also found that early-stage (day 7) and mid-cardiac progenitor cell (CPC) stage (day 14), and late-stage (day 21) iCMCs exhibit different potential for cell transplantation. Our preliminary data favors the day 14 (CPC/iCMC) stage for the transplantation with regards to the maturity and its differentiation potential into cardiomyocytes, endothelial cells and smooth muscle cells. Recent results also indicate the important roles of exosomes (stem cell- or progenitor- derived) play in tissue regeneration. Based on these observations, our central hypothesis states that overexpressing scaRNA20 during iCMCs differentiation and selecting an appropriate differentiation stage (day 14) for cell or exosome treatment would induce superior cardiac repair in the ICM patients. We plan to test our hypothesis by pursuing the following three specific aims. (1) To characterize cardiomyocytes induced from urinary epithelial cells (UE-iCMCs) and determine the role of scaRNAs during differentiation of iPSCs into iCMCs. (2) To determine the therapeutic efficiency of scaRNA20 modulated iCMCs in a SCID mouse chronic ischemic cardiomyopathy (ICM) model. (3) In vitro and in vivo analysis of the paracrine mechanisms of scaRNA20 modulated UE-iCMCs and their exosomes. If successful, this approach will dramatically enhance our ability to perform autologous cell or cell-free exosome therapy for patients with no-option heart diseases.